14683-12-6Relevant articles and documents
Effect of high magnetic field on the fabrication of one-dimensional tellurium microstructures via a solvothermal treatment
Xu, Yongbin,Ren, Zhongming,Cao, Guanghui,Ren, Weili,Deng, Kang,Zhong, Yunbo
, p. 1200 - 1201 (2008)
The magnetic-field-assisted solvothermal approach has been used in the shape-controlled growth of Te microcrystals. By applying a high magnetic field to the reaction system, the shape of obtained Te microcrystals could be changed greatly. Various techniques such as X-ray diffraction and scanning electron microscopy have been used to characterize the obtained products. The results show that the magnetic field plays a key role in the growth behavior of Te microcrystals. The possible cause of magnetic field effects is discussed. Copyright
Mechanism of film growth of tellurium by electrochemical deposition in the presence and absence of cadmium ions
Ku, Jie-Ren,Vidu, Ruxandra,Stroeve, Pieter
, p. 21779 - 21787 (2005)
The growth morphology and the kinetics of a thin film of Te on Au during electrochemical deposition at -62 mV (vs Ag/AgCl/3 M NaCl) have been studied. The deposition conditions are similar to those used previously by us to grow nanowires inside Au nanotubes by electrochemical deposition in the presence of Cd ions (Cd2+). By using electrochemical deposition on a planar Au electrode, we explored the growth of the Te film for two conditions: in the presence of Cd2+ (0.1 mM TeO2 + 1 mM CdSO4 + 50 mM H2SO4 solution) and in the absence of Cd2+ (0.1 mM TeO2 + 50 mM H2SO4 solution). We used several surface investigation techniques to study the growth such as: in situ electrochemical atomic force microscopy (EC-AFM), in situ electrochemical surface plasmon resonance (EC-SPR), electrochemical methods, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). In the presence of Cd2+, in situ electrochemical atomic microscopy showed that Cd 2+ acted as a mediator at the early deposition stage and caused smoothing of the Te deposit obtained. In the absence of Cd2+, Te had an island growth. The electrochemical surface plasmon resonance showed that the deposit was characterized by a slower deposition rate in the presence of Cd 2+ than in the absence of Cd2+. Additionally, the thickness of the film was evaluated using EC-AFM measurements, electrochemical stripping analysis, and EC-SPR. The results obtained from all three measurements agree well with the Te film obtained in the presence of Cd2+, where a continuous and uniform film was formed. In the presence of Cd2+, a Te film with a thickness of 1.04 nm and atomically flat surface was deposited on an ultraflat Au surface. The XPS spectrum showed no significant amount of Cd in the deposit, indicating that the Cd ion acted as a mediator and not as a co-deposition element.
Photoassisted electrodeposition of CdTe layer from ammoniacal basic aqueous solutions
Murase, Kuniaki,Matsui, Masaki,Miyake, Masao,Hirato, Tetsuji,Awakura, Yasuhiro
, p. C44-C51 (2003)
Potentiostatic cathodic electrodeposition of CdTe on gold substrate under irradiation of visible light was studied using basic aqueous electrolytic baths in which Cd(II) and Te(IV) species were dissolved to form Cd(NH3)42- and TeO32- ions, respectively. Both deposition current density and current efficiency for the CdTe deposition were enhanced by photoirradiation and, as a result, the time required for a given amount of deposition was dramatically shortened. The photoirradiation also resulted in a slight increase in cadmium content of the CdTe deposits and, in some cases, elemental Cd was deposited by underpotential codeposition. The cathodic polarization curve under pulsed photoirradiation showed a photoresponse in cathode current at potentials negative to the Nernst potential of CdTe deposition and the photoresponse was observed for wavelengths lower than that corresponding to the bandgap of CdTe, suggesting that the response was due to the CdTe itself growing on the cathode surface. The mechanism of the photoassist is discussed in terms of photoconduction of low-conducting CdTe semiconductors.
Microwave-polythiol Method. A New Route to Preparation of Tellurium with Various Morphologies
Zhu, Ying-Jie,Hu, Xian-Luo
, p. 732 - 733 (2003)
A new microwave-polythiol method has been developed for preparation of tellurium (Te) with various morphologies. 1,2-Ethanedithiol (EDT) was used as both a reducing reagent and a solvent. Reduction of TeO2 by EDT was achieved by microwave-heating at ≤140°C for 30 min. The morphology of Te could be controlled by changing experimental parameters.
Synthesis and Crystal Structure of Tellurium(II) bis(2- methoxycarbonylethanethiolate): A Novel Coordination Mode of Tellurium
Fleischer, Holger,Hennig, Sandra,Schollmeyer, Dieter
, p. 1969 - 1974 (2003)
The tellurium(II) dithiolates Te[SCH2CH2C(O)OCH3] 2, (1), Te[SCH2CH2CH2SC(O)CH 3]2, (2), and Te[SCH2CH2CH 2CH2- SC(O)CH3]2, (3) were synthesized from Te(StBu)2 and the corresponding thiol. All compounds are sensitive toward higher temperatures and light and decompose to elemental tellurium and the disulfide. In the solid state, the Te atom of 1 exhibits the novel Te(S2Te2) coordination mode. Additionally to the two Te-S bonds, each Te atom forms two long Te...Te contacts to neighboring mol-ecules, leading to a coordination number of four and a distorted sawhorse configuration. No intramolecular Te...O interactions are present in the solid state, in accordance with ab initio calculations (MP2/ecp-basis) for the isolated molecule. 125Te NMR shifts of all compounds lay within a narrow range and close to the respective shift of other Te(SCH2R)2 compounds. VT 125Te NMR spectra gave no hint to donor acceptor interactions in solution for any of the compounds and thus corroborate results from IR-spectroscopy, ab initio geometry optimizations, and thermochemical calculations.
Preparation of photocatalytic Au-Ag2Te nanomaterials
Lin, Zong-Hong,Shih, Zih-Yu,Roy, Prathik,Chang, Huan-Tsung
, p. 12330 - 12336 (2012)
A facile approach has been developed for the preparation of various morphologies of Au-Ag2Te nanomaterials (NMs) that exhibit strong photocatalytic activity. Te NMs (nanowires, nanopencils, and nanorice) were prepared from TeO2 in the presence of various concentrations (16, 8, and 4 M) of a reducing agent (N2H4) at different temperatures (25 and 60 °C). These three Te NMs were then used to prepare Au-Ag2Te NMs by spontaneous redox reactions with Au3+ and Ag+ ions sequentially. The Au-Ag2Te nanopencils exhibit the highest activity toward degradation of methylene blue and formation of active hydroxyl radicals on solar irradiation, mainly because they absorb light in the visible region most strongly. All three differently shaped Au-Ag 2Te NMs (10-μg mL-1) provide a death rate of Escherichia coli greater than 80 % within 60-min, which is higher than that of 51 % for commercial TiO2 nanoparticles (100-μg mL-1). Under light irradiation, the Au NPs in Au-Ag2Te NMs enhance the overall photo-oxidation ability of Ag2Te NMs through faster charge separation because of good contact between Ag2Te and Au segments. With high antibacterial activity and low toxicity toward normal cells, the Au-Ag2Te NMs hold great potential for use as efficient antibacterial agents. Copyright
Low dimensional materials: Syntheses, structures, and optical properties of Rb2CuTaS4, Rb2CuTaSe4, RbCu 2TaSe4, K3Ag3Ta2Se 8, and Rb3AgTa2Se12
Wu, Yuandong,N?ther, Christian,Bensch, Wolfgang
, p. 1006 - 1014 (2004)
The new compounds Rb2CuTaS4 (1), Rb 2CuTaSe4 (2), RbCu2TaSe4 (3), K 3Ag3Ta2Se8 (4), and Rb 3AgTa2Se12 (5) have been synthesized by the reactive flux method at 773 or 873 K. Their crystal structures were determined by single crystal X-ray diffraction. Crystal data for 1: space group Fddd, a = 5.598(1), b = 13.512(4), c = 23.854(5) ?, Z = 8; Crystal data for 2: space group Fddd, a = 5.782(1), b = 13.924(3), c = 24.653(5) ?, Z = 8; Crystal data for 3: space group C2cm, a = 5.7218(3), b = 19.2463(13), c = 7.7456(5) ?, Z = 4; Crystal data for 4: space group C2/c, a = 25.1374(19), b = 6.1007(3), c = 14.4030(11) ?, β = 119.703(8), Z = 4; Crystal data for 5: space group P21/n, a = 9.8186(6), b = 13.7462(11), c = 15.7368(9) ?, β = 96.681(7)°, Z = 4. The compounds 1 and 2 are built up of ∞1[CuTaQ4]2- anionic chains which are formed by edge-sharing CuQ4 and TaQ4 tetrahedra. The rubidium cations are located between the chains. Compound 3 consists of ∞2[Cu2TaSe4]- anionic layers separated by rubidium cations. The anionic layers are formed by ∞1[CuTaSe4]2- chains which are connected by CuSe4 tetrahedra that share common edges with the TaSe4 tetrahedra of neighboring chains. In compound 4 ∞1[Ag3Ta2Se8] 3- anionic chains are found which are separated by potassium cations. These chains are formed by successive corner sharing of AgSe4 tetrahedra and edge sharing between AgSe4 and TaSe4 tetrahedra. All three structures are closely related with the sulvanite (Cu 3VS4) structure type. Compound 5 contains a one dimensional ∞1[AgTa2Se12] 3- anionic chain formed by interconnection of AgSe4 tetrahedra and [Ta2Se11] units. In the structure three monoselenide, three diselenide, and one triselenide anions are found. Raman and far-IR spectroscopic data of compounds 1 and 4 were collected and an interpretation is presented.
Simple synthesis of ultra-long Ag2Te nanowires through solvothermal co-reduction method
Xiao, Feng,Chen, Gang,Wang, Qun,Wang, Lin,Pei, Jian,Zhou, Nan
, p. 2382 - 2388 (2010)
Ultra-long single crystal β-Ag2Te nanowires with the diameter of about 300 nm were fabricated through a solvothermal route in ethylene glycol (EG) system without any template. The long single crystal wires were curves, with high purity, well-crystallized, and dislocation-free and characterized by using X-ray powder diffraction (XRD), Differential scanning calorimetry (DSC) analysis, X-ray photoelectron spectroscope (XPS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and high-resolution transmission microscopy (HRTEM). The detailed topotactic transformation process from particles into single crystal wires was studied. Furthermore, the electrical conductivity and Seebeck coefficient have been systematically studied between 300 and 600 K.
Mesostructured assemblies of ultrathin superlong tellurium nanowires and their photoconductivity
Liu, Jian-Wei,Zhu, Jian-Hua,Zhang, Chuan-Ling,Liang, Hai-Wei,Yu, Shu-Hong
, p. 8945 - 8952 (2010)
Well-defined periodic mesostructures of hydrophilic ultrathin Te nanowires with aspect ratios of at least 104 can be produced by the Langmuir-Blodgett technique without any extra hydrophobic pretreatment or functionalization. Packing the arrayed nanowire monolayers will allow construction of nanomesh-like mesostructures or more complex multilayered structures composed of ultrathin nanowires on a planar substrate. The well-organized monolayer of Te nanowires with periodic mesostructures can be readily used as a stamp to transfer such mesostructured nanopatterns to other substrates or can be embedded within a polymer matrix. The mesostructures of ultrathin Te nanowire films show reversibly switched photoelectric properties between the lower- and higher-conductivity states when the light is off and on, and the photocurrent is influenced by the light intensity and the number of mesostructured nanowire monolayer films. This method can be extended for fabrication of other mesostructured assemblies of ultrathin nanowires or nanotubes.
Structural changes of amorphous GeTe2 films by annealing (Formation of metastable crystalline GeTe2 films)
Fukumoto, Hirofumi,Tsunetomo, Keiji,Imura, Takeshi,Osaka, Yukio
, p. 158 - 162 (1987)
Amorphous GeTe2 films with the thickness ～0.5 μm, prepared by sputtering technique, transform into the crystalline GeTe 2 films with the isomorphic structure to β-cristobalite, cubic SiO2, at Ta(annealing temper
